Compression
Check engine mechanical condition using a compression gauge, vacuum gauge or engine analyzer. See engine analyzer manual for specific instructions.
| WARNING | DO NOT use ignition switch during compression tests on fuel injected vehicles. Use a remote starter to crank engine. Fuel injectors on many models are triggered by ignition switch during cranking mode, which can create a fire hazard or contaminate engine oiling system. |
| Application | Specification | |
|---|---|---|
| Compression Ratio | ||
| 2.0L | 9.0:1 | |
| 3.0L | 8.9:1 | |
| Compression Pressure | ||
| 2.0L | 171 psi (12.0 kg/cm 2 ) | |
| 3.0L | 173 psi (12.2 kg/cm 2 ) | |
| Max. Variation Between Cylinders All Models | 14 psi (1.0 kg/cm 2 ) | |
COMPRESSION SPECIFICATIONS
Exhaust System Backpressure
Exhaust system can be checked with a vacuum or pressure gauge. If using a pressure gauge, remove HO2S sensor. Connect a 1-10 psi pressure gauge and run engine at 2500 RPM. If exhaust system backpressure is greater than 1 3/4 - 2 psi, exhaust system or catalytic converter is plugged.
If using a vacuum gauge, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restrictions.
FUEL SYSTEM
| WARNING | Always relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
FUEL PRESSURE RELEASE
Disconnect fuel pump harness connector under rear seat. Start engine. After engine stalls, turn ignition off. Disconnect negative battery cable. Reconnect fuel pump harness connector.
Spark (Spark Plug)
Connect spark plug to a high tension cable. Ground outer electrode (main body of spark plug), and crank engine. Spark should occur in discharge gap between electrodes. Spark plug gap should be .039-.043" (1.0-1.1 mm).
Ignition Coil Power Source
Disconnect coil primary connector. Turn ignition on. Using voltmeter, check voltage between positive terminal and ground. Battery voltage should exist.
Ignition Coil Resistance
- Using an ohmmeter, measure primary coil resistance for cylinders No. 1 and 4 between coil connector terminals No. 1 and 3. Measure resistance for cylinders No. 2 and 3 between connector terminals No. 2 and 3. (Scheme 5) See «DIS IGNITION COIL RESISTANCE»(ref-16486-S09067343952000122900000) table.
- To measure secondary coil resistance, disconnect ignition coil connector. Measure resistance between coil towers No. 1 and 4 and between coil towers No. 2 and 3. See «DIS IGNITION COIL RESISTANCE»(ref-16486-S09067343952000122900000) table. Replace coil if readings are not within specification.
| Application | Primary | Secondary |
|---|---|---|
| Sonata 2.0L | .77-.95 | 10,300-13,900 |
DIS IGNITION COIL RESISTANCE - Ohms @ 68°F (20°C)
Scheme 5
Power Transistor
- Disconnect connector from power transistor. To check power transistor for cylinders No. 1 and 4, apply 1.5 volts between power transistor terminals No. 3 (negative) and No. 4 (positive). (Scheme 6)
- Using analog ohmmeter, check continuity between terminals No. 3 (positive lead) and No. 5 (negative lead). With voltage applied to terminal No. 4, continuity should exist. With voltage removed from terminal No. 4, continuity should not exist.
- To check power transistor for cylinders No. 2 and 3, apply 1.5 volts between power transistor terminals No. 2 (positive) and No. 3 (negative). Using analog voltmeter, check for continuity between terminals No. 1 (negative lead) and No. 3 (positive lead). With voltage applied to terminal No. 2, continuity should exist. With voltage removed from terminal No. 2, continuity should not exist.
Scheme 6
Spark (Coil)
Check for spark at coil wire. Hold wire about 1/4" from an engine ground, and crank engine. If spark is produced, coil is okay. If spark is not produced, use a voltmeter to check voltage at negative side of coil (tach signal) while cranking engine. If voltage does not exist, see IGNITION COIL POWER SOURCE below. If voltage does not fluctuate, check coil wiring, power transistor, ECU and distributor assembly. If voltage fluctuates, check coil resistance, coil wire and connections.
Connect spark plug to a high tension cable. Ground outer electrode (main body of spark plug) and crank engine. Spark should occur in discharge gap between electrodes. Spark plug gap should be .039-.043" (1.0-1.1 mm).
Disconnect coil primary connector. Turn ignition on. Using voltmeter, check voltage between positive terminal and ground. Battery voltage should exist.
- Remove primary and secondary leads from ignition coil. Using an ohmmeter, check primary resistance between positive and negative terminals of coil. See «EIS IGNITION COIL RESISTANCE»(ref-16486-S30699251162000122900000) table.
- Check secondary resistance between ignition coil positive terminal (Black/White wire) and ignition coil tower. See «EIS IGNITION COIL RESISTANCE»(ref-16486-S30699251162000122900000) table. Replace coil if readings are not within speci-fication.
| Application | Primary | Secondary |
|---|---|---|
| Sonata 3.0L | .72-.88 | 10,300-13,900 |
EIS IGNITION COIL RESISTANCE - Ohms @ 68°F (20°C)
Power Transistor (3.0L)
- Disconnect connector from power transistor. Apply 3.0 volts between power transistor terminals No. 1 (positive) and No. 2 (negative). (Scheme 7)
- Check continuity between terminals No. 2 and 3. With voltage applied to terminal No. 1, continuity should exist. With voltage removed from terminal No. 1, continuity should not exist. Replace power transistor if continuity is not as specified.
Scheme 7
IDLE SPEED & IGNITION TIMING
Ensure idle speed and ignition timing are set to specification. For adjustment procedures, see ON-VEHICLE ADJUSTMENTS article.
SUMMARY
If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to SELF-DIAGNOSTICS article. If no hard codes are found in self-diagnostics, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.